1. Field of the Invention
The present invention generally relates to an apparatus for relieving hydraulic pressure in a hydraulic hose connected with hydraulically powered equipment in which the hose supplies hydraulic pressure to the equipment from a source of hydraulic pressure or returns hydraulic pressure from the equipment to a hydraulic fluid reservoir. The hydraulic hose is separably connected to a hydraulic source by a quick coupler including a male and female component each of which includes a valve that is open as long as the quick coupler components are connected but will immediately close when the quick coupler components are disconnected thereby trapping hydraulic pressure in the hose. Any entrapped hydraulic pressure within the hose exerts pressure on the valve in the quick coupler component on the hose which makes it quite difficult to reconnect the male and female components of a quick coupler when reconnecting the hose to a hydraulic pressure source.
The tool of this invention includes a quick coupler component, either male or female which has been modified by removing the valve and substituting a screw thread member threadedly engaged in the quick coupler component and oriented in the same position as the removed valve. This enables the screw threaded member to engage and open the valve in the quick coupler component connected with the hose to relieve hydraulic pressure in the hose. The screw threaded member is provided with a T-handle for ease of rotation thereof.
When the end of the screw threaded member opposed to the valve in the quick coupler component on the hose is threaded toward and engages the valve and moves the valve off the seat in the quick coupler component connected to the hose, hydraulic pressure is relieved from the hose. This enables the quick coupler component on the hose to then be easily connected to the quick coupling component on a source of hydraulic pressure since the coupling operation of the quick coupler components does not require that the valve in the quick coupler component on the hose be forced open when coupling the two component of the quick coupler. The tool also includes a small tube or pipe communicated with the interior of the modified quick coupler component to direct the discharge of hydraulic pressure away from a person using the tool or into a receptacle to catch any hydraulic fluid discharged from the hose when relieving the pressure in the hose.
2. Description of the Prior Art
Hydraulically powered equipment is used for various purposes such as on various agricultural equipment, industrial equipment and the like and usually includes a hydraulic ram in the form of a piston and cylinder assembly, a hydraulic motor or the like connected to a source of hydraulic pressure by flexible hoses with control valves being provided for controlling operation of the hydraulically powered equipment. In many installations, such as agricultural implements, the hydraulic hoses are connected to another hose or a tractor mounted hydraulic control valve by a quick coupler which includes a male component and a female component which are quickly and easily connected by merely inserting the male component into the female component with interconnecting latching or detent structure securing the two components in connected, sealed relation. Each of the two components in the quick coupler have a spring biased valve, usually a steel ball valve, engaged with a valve seat when the quick coupler components are disconnected. When the quick coupler components are connected, the valves contact each other and move each other away from the valve seat thereby communicating the hose with another hose or a source of hydraulic pressure such as the tractor mounted hydraulic control valve.
When the agricultural implement is to be disconnected from the tractor, the hydraulic control valve is closed and the quick coupler components disconnected by manually releasing the latch or detent structure with the valves closing when the quick coupler components are separated. However, the steel ball in the quick coupler connected to the hose is pushed against its seat by the pressure within the hose which prevents hydraulic fluid or oil in the hose from draining onto the ground surface or the like. Frequently, the hydraulically powered equipment on the agricultural implement will remain pressurized due to movement of a component of the agriculture equipment in a manner so that the hydraulically powered unit on the agricultural implement will apply force to the hydraulic fluid to maintain relatively high pressure in the hose. Then, when it is desired to recouple the quick coupler component on the hose to a quick coupler component connected to the tractor mounted hydraulic control valve, or to connect it to another hose, it is quite difficult to move the steel ball valve in the quick coupler component on the hose away from the valve seat. Heretofore, pressure has been relieved by taking the hose and the quick coupler unit attached thereto and beating the steel ball against a hard object such as the frame of an agricultural implement. This procedure is time consuming since the steel ball is pushed off its seat for only a very small part of a second thus releasing only a tiny amount of pressurized fluid. Also, each time the steel ball is hit against an object and temporarily opened, a highly pressurized squirt of hydraulic fluid or oil sprays out in all directions which not only deposits hydraulic fluid onto the ground surface but also on agricultural implements and the person trying to relieve pressure in the hose. Efforts have been made to relieve pressure from various pressurized sources. The following U.S. patents relate to coupling devices and devices for relieving pressure.
______________________________________ 929,561 3,718,057 950,263 3,730,221 1,392,231 3,855,882 2,235,572 5,054,179 2,649,825 ______________________________________
While the above listed patents disclose various types of valve couplings and certain of the patents include tools for relieving pressure, they do not include a quick coupler component, either male or female, mounted on a hydraulic hose such as those connected to a hydraulic ram or other hydraulic motor on an agricultural implement, industrial machine or the like. The prior patents do not disclose a tool to relieve pressure in a hose which has a residual pressure therein when disconnected from a hydraulic pressure source which makes the quick coupler on the hose very hard to couple to another hose or other hydraulic pressure source such as a control valve which normally controls pressure to the hydraulically powered equipment. The tool of this invention is actually a modified quick coupler component from which the valve has been removed and replaced by a screw threaded member oriented in the same location as the valve for engagement with and opening the valve on a quick coupling component on a hose connected to the hydraulically operated equipment. The tool enables the valve to be quickly and easily opened for relieving hydraulic pressure in the hose to enable it to be easily connected to a quick coupler component on another hose or on a control valve connected with a source of hydraulic pressure.